It was another celebrity packed weekend here in Sin City. Sinking their teeth into all that is Vegas were Twilight stars Ashley Greene & Kellan Lutz. Greene was in town to celebrate her 22nd birthday on Saturday. The celebration began on Thursday as the duo, and fellow actress Brittany Snow, took in Zumanity. On Friday the birthday girl and friends saw Tony and Tina’s wedding at new home Planet Hollywood Resort & Casino and then headed to hotspot Prive to finish off the festivities. The group got comfortable at a VIP banquette by the DJ booth and started drinking champagne, Grey Goose with mixers and Patron Tequila. Greene stuck to champagne and was extremely polite thanking Prive’s staff several times for their assistance. At the stroke of Midnight, Greene toasted with her friends to her birthday and was given a cake to honor the occasion. The group danced and partied until 2 a.m.

Over at The Bank, actress and singer Haylie Duff celebrated her 24th birthday with beau Nick Zano, pals Channing Tatum and Jenna Dewan, among other Hollywood hotties. The festive evenning started out with a dinner for 14 at celebrity-frequented Yellowtail Sushi Restaurant & Bar (client) at Bellagio where Haylie, Nick, Channing (starring as “Duke” in upcoming G.I. Joe film) and Jenna and company enjoyed the culinary delights of up-and-coming celebrity chef Akira Back. In between sake bombs, the party savored Back’s signature tuna pizza and trademark rock shrimp dishes. The group then headed over to The Bank where Duff and Zano were in high spirits spotted dancing and smooching all night only breaking to down shots of Patron with friends or to throw back vodka with Red Bull cocktails. Tatum and Dewan were also seen canoodling throughout the party. Haylie was surprised and delighted when presented with a beautiful pink cake created by Jean-Philippe Patisserie. Also spotted at Duff’s party were the striking Shayne Lamas, winner of season 12 of Bachelor, Brett Claywell of the new show Dollhouse and of One Tree Hill fame, and Robert Kardashian, Jr.

Finally, Drew Barrymore (left), celebrating her 34th birthday Saturday at The Palazzo Las Vegas with a group of friends including fellow birthday girl, Ellen Page of “Juno” and Kristen Wiig of “Saturday Night Live.” Page and Wiig are starring in “Whip It,” Barrymore’s directorial debut. Barrymore’s group strolled through The Palazzo casino singing and dancing to old-school jams on her boom box while walking up to their suites. Barrymore stayed in the 3,000 square-foot, two-bedroom Penthouse Suite, which overlooks the Las Vegas Strip. They dined at Lavo, and had birthday cakes on the hookah patio. Page was celebrating her 22nd birthday…